Bucking the weak broader market, shares of Vijay Mallya-led Kingfisher Airlines on Wednesday soared over 18 per cent higher on the bourses, as investors rushed in to buy the stock after a heavy battering of last few days. The robust buying activities came a day after Mallya assured the investors that the air carrier did not face any closure risks and outlined plans to arrange necessary funds and to lower its borrowing, fuel and operational costs.